Inking and dampening apparatus for printing press

ABSTRACT

The cam controlling the application of the dampener to the dampening area of a printing plate mounted on the plate cylinder of a printing machine is constructed to adjust the amount of dampener needed to print the image in the printing area of any given printing plate.

United States Patent 1 1 Wolff 1 11 0 3,744,413 451 July 10,1973

[ 1 INKING AND DAMPENING APPARATUS FOR PRINTING PRESS 75 Inventor: Edwin K. Wolff, Stockholm, NJ. [73] Assignee: NJM, Inc., HolaokemNJ.

[22] Filed: Apr. 12, 1971 [211 App]. No.: 133,273

[52] US. Cl. 101/142, 101/148 [51] Int. Cl B411 7/08, B411 25/16 [58] Field of Search 101/147, 148, 136,

[56] References Cited 111 131) STATES PATENTS 5/1912 Firm 10/1970 Roozee v 2/1900 Brooke et al 101/148 2,389,730 11/1945 ller ..101/147 4 3,448,686 6 1969 3611mm"... 101/148 x 302,244 7/1884 Forbes ..101/136 1,568,919 l/1926 M61156: '8]. ..1o1 142 3,370,54 2/1968 141 1161.; ..1o1/142x FOREIGN PATENTS OR APPLICATIONS- 942,898 11/1963 0166113 1616 ..101/148 Prirriary Ekaminef-Clyde l. Coughen'our Anbmey-Sylvester J. Liddy, John .1. Hart, Joe E. Danielsand Charles E; Baxley Y 57 1 ABSTRACT.

The cam controlling the application of the dampener to the dampening area of a printing plate mounted on the plate cylinder of a printing machine is constructed to adjust the amount of dampener needed to print the image in the printing area of any giyen printing plate.

'7 Claims, 4 Drawing Figures Pmzmiowuoms SHEEI 1 0F 2 INVENTOR.

DW/N K. WOLFF Arm/21m FIG.

INKING AND DAMPENING APPARATUS FOR PRINTING PRESS thereof with a suitable dampening material, such as water. The invention is especially advantageous for use with a printing press of the type dislcosed in US. Pat. No. 3,610,147, issued Oct. 5, 1971 for Improvements in Offset Printing. In the use of the printing press therein disclosed, the printing plate or plates provide a plurality of image areas, each of which is associated with a dampening area. The image and dampening areas employed in such disclosed printing press are of fixed extent and the dampening areas are supplied with the dampener through mechanism which include cams of fixed length mounted on the plate cylinder. The several image areas provided on the plate cylinder each applies to a common blanket, an ink image constituted of a particular ink composition and the resulting composite multi-composition ink image is then printed on suitable paper stock. It will be appreciated that in the use of such a construction one or more of the image areas may be provided with a relatively small portion of the complete composite image to be offset onto the blanket. Such a small image portion therefore, will require a smaller amount of ink than another image area provided with a larger portion of the complete composite image. However, as previously indicated, printing machines of the type disclosed in the aforesaid application supply for each image area the same amount of dampener, regardless of the amounts of ink that need be applied to such image areas.

It is the object of the present invention to provide a dampening arrangement whereby, even though the dampening areas which are associated with a plurality of image areas on a plate cylinder are of fixed extent, variable quantities of a dampener may be selectively applied to such dampening areas so as to obtain the proper balance between the amounts of dampener and ink composition which is applied to each of such image areas.

For a better understanding of the invention, as well as the features thereof, reference is made to the following description which should be read in connection with the accompanying drawings, in which FIG. 1 is a side elevational partial view of the plate, blanket and impression cylinders in an offset printing machine of the type disclosed in said U.S. Pat. No. 3,610,147 and embodying the present invention;

FIG. 2 is a sectional view taken through the periphery of the plate cylinder and looking along the line 22 of FIG. 1, the view showing the offset printing plate in position on the cylinder surface;

FIG. 3 is a perspective view of the parts shown in the left hand side of FIG. 2 with the offset printing plate omitted; and

FIG. 4 is a schematic plan view of the dampening and image areas provided on the printing plate.

The portion of the offset printing machine illustrated in FIG. 1 of the drawings includes a plate cylinder .of usual construction having associated therewith rolls for applying ink and dampener to the plate 11 mounted thereon. The ink is shown applied in three different ink compositions by three separate inking mechanisms 12, 13 and 14 of customary construction. A dampening unit 15 of known construction applies the dampening or wetting solution, for example water, to the plate 11. The applications of the three differently constituted inks by the inking rolls of the mechanisms l2, l3 and 14 to three image areas 12', 13' and 14', respectively, provided on the plate 11, are controlled by two sets of earns 12', 13" and 14", respectively, projecting from the periphery of the cylinder 10 at each end thereof (note FIG. 2). Associated with the cams 12", 13" and 14" at each end of the cylinder are three cams generally designated l8, l9 and 20, for controlling the applying roll of the dampening unit 15 so that applications of the dampener are applied to the dampening areas 21,22 and 23 located in advance of the image areas 12', 13 and 14', respectively, as the plate surface 24 of the cylinder 10 is traveling in the direction of the arrows 25 in FIGS. 1, 3 and 4 of the drawings. The plate 11 may be of any suitable construction, such as the thin, destructible, unitary plate 11 shown on which all of the three image areas and three dampening areas are provided, or as previously indicated, instead of such a unitary plate, three separate plates on each of which an image area and a dampening area may be provided. It will be noted that the unitary plate 11 shown is mounted on the cylinder 10 so that its ends 11 are locked in a slot 26 provided in the cylinder 10 so that on the printed stock plate gaps of the width of such slot 26 will appear intermediate the printed complete composite items unless a control of the paper stock feed is exercised in the manner disclosed in said US. Pat. No. 3,610,147. The portion of the complete composite item in each image area of the plate 11 is offset onto a blanket cylinder 30 during each complete revolution of the latter. As the blanket cylinder revolves three times for every revolution of the plate cylinder 10, all of the images constituting the complete composite item will have been applied to the blanket cylinder at the end of such three revolutions thereof. The complete composite item offset onto the blanket cylinder is transferred to the paper stock with the cooperation of an impression cylinder 35 in a known manner.

As will be observed in FIG. 4 of the drawings, the plate 11 is divided to provide three image areas 12', 13' and 14' of equal circumferential length separated by two dampening areas 22 and 23 of a length that is similar to that of the image areas. The advance end of the plate however, may be provided with a dampening area 21 having a length which differs from that of the other dampening areas 22 and 23, dependent on the length of the image area which has been selected and the circumferential length of the plate surface of the particular cylinder being used between the edges of the slot gap 26 therein. In the printing plate shown, the length of the dampening area 21 is slightly less than that of the dampening areas 22 and 23, but this is not sufficient to effect the quality of the printing produced from the image area 12.

It will be seen more clearly from a consideration of FIGS. l-3 of the drawings, that the printing earns l2", l3" and 14" and the main portion 45 of a dampening roll lifting cam are in the form of rings which are mounted on shoulders 40 formed on each end of the plate cylinder 10 and are fixedly secured in position thereon by bolts 41 which threadedly engage the peripheral end wall portions of the cylinder. The printing cam rings and the main dampening cam ring 45 are separated by spacer rings 42 which are also secured on the shoulders 40 by the bolts 41. The main dampener cam ring 45 is shaped to provide three spaced dampener cam portions 18, 19 and and intermediate such portions is high enough to provide a rim bordering an outer reduced portion 46 of the cylinder plate surface 24. The shoulder formed by such reduced surface portion 46, and the ring 45 thus form a guideway in which are slidably mounted three adjustable dampening roll cam segments 18", 19" and 20". As will be seen more clearly in FIG. 3 of the drawings, each cam segment is composed of an arcuately shaped slide 47 which seats on the surface portion 46 and is provided with an elongated slot 48 through which extends an adjusting screw 49 threadedly engaged with a female thread provided at a suitable location in such surface portion 46. The outer edge of the arcuate slide 47 has integrally formed therewith a cam member 50 having a height similar to that of its associated cam portion 18, 19 or 20' and engaging the latter in side-by-side relation so that the two form the complete dampener earns 18, 19 or 20. The advanced or leading end 50' of the cam member 50 is inclined to facilitate a dampening roll riding up on such member.

It will be understood from the foregoing, that by adjusting a segment member 18", 19" or 20" with relation to its associated cam portions 18', 19 and 20', respectively, it is possible to adjust the length of time that the dampening roll will be in contact with the dampening area on the plate that is controlled by such segment member and its associated cam portion. By so varying the length of time that such dampening roller comes into engagement with such dampening arm it is possible to adjust the amount of water delivered to its associated following printing area to provide the proper dampening for the image that is to be offset in the printing area. As this control of the dampening is selectively variable, the amount of dampener delivered to each of the image areas can be made to vary dependent on the size of the image to be offset from such area. Thus, as is shown in FIG. 4 of the drawings, the image area 12' has a small image to be offset. Accordingly, the segment member 18" is adjusted with relation to camportion 18 so that the dampener roll will only contact the shaded area 21 of the dampening area 21 associated with such image area 12. The image area 13' has an image which takes up the entire area, so the adjustment of the segment member 19" is made such that it will not reduce the contact of the dampener roll in the dampening area 22. In the image area 14', the image is not quite as small as the image in image area 12', so its associated segmant member 20" is adjusted to reduce the range of contact of the dampening roll in the dampening area 23 to a lesser extent, as indicated by the shaded portion 23'.

It will thus be understood that by proper use of the segment members 18', 19" and 20" the dampening can selectively be made variable to suit the size of the image to be printed in each image area of the plate, or plates that may be used in the machine. The cam segments 18", 19" and 20 are preferably made of a length that is equal to the length of the dampening areas with which they are to be associated so that they can completely block contact of the dampening roll with any of such areas. This makes it possible to use both wet and dry offset plates on the same plate cylinder. When it is desired to combine dry and wet offset plates in a printing operation such as is disclosed in application Ser. No. 133,274 filed Apr. 12, 1971 by Robert .l. Crissy, for System of and Apparatus for Printing Business Forms, care must be taken to either use plates all of the same thickness, or to provide a backing for the wet offset plates, or to machine the plate cylinder surface 24 to accommodate both wet and dry offset platesin order to accomplish proper printing quality.

What is claimed is:

1. In a printing press having a rotatable plate cylinder provided with an image area and an adjacent dampening area of fixed extent located in advance of said image area in the direction of rotation of such cylinder,

means for dampening said dampening area only comprising a dampening roll and a lifting cam for maintaining said dampening roll out of contact with said image area, and an inking member adapted to contact both the dampening area and the image area so as to pick up dampener from the dampener area and thereby apply both dampener and ink to the image area, said lifting cam comprising a cam member fixed to said plate cylinder and extending along the circumferential length of said image area, the position of said fixed cam member relative to said plate cylinder and the length thereof being such as to maintain said dampening roller out of contact with said image area and to permit such roller to engage with said dampening area throughout the whole extent thereof, a cam segment adjustably associated with the leading end of said fixed cam member and selectively movable relative to such cam member to vary the extent of the contact of said dampening roll with said dampening area from a contact extending to the full extent of such area to a contact of materially lesser extent and thereby to control the amount of dampener applied to such area and picked up by said inking member, and means for releasably securing said cam segment in an adjusted position relative to said fixed cam member.

2. In a printing press as defined in claim 1, in which said lifting cam is composed of a ring having a plurality of said cam members formed thereon, means for securing said ring to a peripheral edge portion of said cylinder, a cam segment associated with each of said cam members and slidably mounted on the peripheral edge portion of the cylindrical plate surface of said cylinder, and means releasably securing said cam segments to said cylinder plate surface.

3. In a printing press as defined in claim 2, in which said cam ring forms a rim around the edge portion of said cylinder plate surface, and in which said peripheral edge portion of such surface is reduced and forms the inner wall of an annular guideway between such rim and the shoulder formed by such reduced edge portion and the main portion of said cylinder plate surface, and in which said segments are slidably mounted in said guideway.

4. In a printing press having a rotatable cylinder, means for mounting on said cylinder printing media including at least one wet offset printing media, and provided with a plurality of separated images for printing a multi-image item on a backing, means for applying ink to all of the separated images on said printing media, means for applying dampening material to the wet offset printing media including a dampening area on said cylinder of fixed extent located adjacently in ading said dampening material applying means to control the extent of the application of dampening material to said dampening area and thereby to control the amount of dampener to be applied to said wet offset printing media, means for contacting said inking means with said dampening area before contacting said wet printing media.

5. In a printing press as defined in claim 4, in which the printing media mounted on said cylinder includes at least one dry offset printing media, and in which said selectively operable means is constructed and arranged to selectively operate said dampening material applying means to cause the latter to apply dampening material to said wet offset printing media and to prevent the application thereby of dampening material to said dry offset printing media.

6. In a printing press having a rotatable cylinder provided with a printing segment and a non-inktreceptive non-printing segment, a dampening roller adapted to contact said non-printing segment, means movably mounted on said cylinder and selectively operable to control the extent of contact of said dampening roller with said non-printing segment, whereby the amount of dampener applied so such segment is selectively controlled, and means to prevent said dampening roller from contacting said printing segment, and an inking member subsequently contacting both the dampener deposited on said non-printing segment and said printing segment to apply to said printing segment a dampener ink mixture in which the amount of dampener is comparable to the amount applied to said non-printing segment.

7. In a printing press as defined in claim 6, in which said cylinder is provided with a plurality of alternately arranged printing segments and non-printing segments, at least one of said printing segments being a wet offset printing segment, and at least one of said printing segments being a dry offset printing segment, in which said dampening roller is adapted to contact all of said nonprinting segments, and in which said movable means is selectively operable to permit said dampening roller to contact the non-printing segment in advance of the wet offset printing segment and to preventthe contact of said dampening roller with the non-printing segment in advance of the dry-offset printing segment. 

1. In a printing press having a rotatable plate cylinder provided with an image area and an adjacent dampening area of fixed extent located in advance of said image area in the direction of rotation of such cylinder, means for dampening said dampening area only comprising a dampening roll and a lifting cam for maintaining said dampening roll out of contact with said image area, and an inking member adapted to contact both the dampening area and the image area so as to pick up dampener from the dampener area and thereby apply both dampener and ink to the image area, said lifting cam comprising a cam member fixed to said plate cylinder and extending along the circumferential length of said image area, the position of said fixed cam member relative to said plate cylinder and the length thereof being such as to maintain said dampening roller out of contact with said image area and to permit such roller to engage with said dampening area throughout the whole extent thereof, a cam segment adjustably associated with the leading end of said fixed cam member and selectively movable relative to such cam member to vary the extent of the contact of said dampening roll with said dampening area from a contact extending to the full extent of such area to a contact of materially lesser extent and thereby to control the amount of dampener applied to such area and picked up by said inking member, and means for releasably securing said cam segment in an adjusted position relative to said fixed cam member.
 2. In a printing press as defined in claim 1, in which said lifting cam is composed of a ring having a plurality of said cam members formed thereon, means for securing said ring to a peripheral edge portion of said cylinder, a cam segment associated with each of said cam members and slidably mounted on the peripheral edge portion of the cylindrical plate surface of said cylinder, and means releasably securing said cam segments to said cylinder plate surface.
 3. In a printing press as defined in claim 2, in which said cam ring forms a rim around the edge portion of said cylinder plate surface, and in which said peripheral edge portion of such surface is reduced and forms the inner wall of an annular guideway between such rim and the shoulder formed by such reduced edge portion and the main portion of said cylinder plate surface, and in which said segments are slidably mounted in said guideway.
 4. In a printing press having a rotatable cylinder, means for mounting on said cylinder printing media including at least one wet offset printing media, and provided with a plurality of separated images for printing a multi-image item on a backing, means for applying ink to all of the separated images on said printing media, means for applying dampening material to the wet offset printing media including a dampening area on said cylinder of fixed extent located adjacently in advance of the wet offset printing media and means operative to apply dampener to such dampening area but not to the area occupied by the printing media, and means mounted on said cylinder and selectively operating said dampening material applying means to control the extent of the application of dampening material to said dampening area and thereby to control the amount of dampener to be applied to said wet offset printing media, means for contacting said inking means with said dampening area before contacting said wet printing media.
 5. In a printing press as defined in claim 4, in which the printing media mounted on said cylinder includes at least one dry offset printing media, and in which said selectively operable means is constructed and arranged to selectively operate said dampening material applying means to cause the latter to apply dampening material to said wet offset printing media and to prevent the application thereby of dampening material to said dry offset printing media.
 6. In a printing press having a rotatable cylinder provided with a printing segment and a non-ink receptive non-printing segment, a dampening roller adapted to contact said non-printing segment, means movably mounted on said cylinder and selectively operable to control the extent of contact of said dampening roller with said non-printing segment, whereby the amount of dampener applied so such segment is selectively controlled, and means to prevent said dampening roller from contacting said printing segment, and an inking member subsequently contacting both the dampener deposited on said non-printing segment and said printing segment to apply to said printing segment a dampener ink mixture in which the amount of dampener is comparable to the amount applied to said non-printing segment.
 7. In a printing press as defined in claim 6, in which said cylinder is provided with a plurality of alternately arranged printing segments and non-printing segments, at least one of said printing segments being a wet offset printing segment, and at least one of said printing segments being a dry offset printing segment, in which said dampening roller is adapted to contact all of said non-printing segments, and in which said movable means is selectively operable to permit said dampening roller to contact the non-printing segment in advance of the wet offset printing segment and to prevent the contact of said dampening roller with the non-printing segment in advance of the dry-offset printing segment. 